fix: Deduplicate Kubeflow steering committee member in the member field

[zijianjoy]

because github doesn't allow role in both admins and members.

[google-oss-prow[bot]]

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This pull-request has been approved by: terrytangyuan

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Needs approval from an approver in each of these files: - ~~[OWNERS](https://github.com/kubeflow/internal-acls/blob/master/OWNERS)~~ [terrytangyuan] Approvers can indicate their approval by writing `/approve` in a comment Approvers can cancel approval by writing `/approve cancel` in a comment

[zijianjoy]

/retest